Rotary lithographic press with drive for press rolls

ABSTRACT

An offset printing machine having a drive mechanism for the plate cylinder and rolls comprising a sprocket and chain mechanism for conjointly rotating the parts. The distributor rolls including means for axial reciprocation.

Mc1ndoe....

1,607,931 11/1926 White.... 2,276,525 2,312,053 2,448,975 2,520,688 2,581,687

Trotter.........

[72] Inventors: Jamel .llurny, No. 4-0 Hlavni, Sebranice; Ar-

2/1943 lRobbins et a1.

9/1948 Harrold ct 8/1950 Meyer et a1. 1/1952 [22] Filed:

McWhorter [21] Appl. No.:

101/ Brodie ............101/350 X Ghormley, Jr. et a1. 3,173,361 3/1965 Ver1ik..................... 3,186,338 6/1965 Peyrebrune ct 3,283,741 11/1966 [30] Foreign Application Priority mm Oct. 4, 1968 Czechoslovakia 6885/68 Primary ExaminerJ. Reed Fisher [52] ILLS. (11..................,.............11011111 12,101/148,101/350 Attorney-Richard Low and Murray Schaffer ABSTRACT [51] 112111.111. [58] ii ieido1Senrch..................

An offset printing machine having a drive mechanism for the plate cylinder and rolls comprising; a sprocket and chain Rem-mm Claw mechanism for conjointly rotating the parts. The distributor UMTED STATES y N rolls including means for axial reciprocation.

618,253 Meyrueis....................,..........101/349 7(Iln1ms,3ll)rnvving Figures PATENTEDJAN18 m2 sum 1 or 2 3635167 J AQJZEF C EQVZ IINVENTOR Em "'7 W &

ATTORNEY PATENTED MN? 81972 JaseF JURN HRMoT GER flNVENTOR K/w ATT ROTARY LITIIUGITAIIIIIMI IIEIESS WITH DIEIIIWIE IFUIII' WMESS liltUlLLS BACKGROUND OF THE INVENTION The present invention relates to offset printing machines and in particular to mechanisms for mounting and driving the several rollers thereof.

In conventional offset printing machines damping rolls, applicator rolls and distributor rolls are either driven by a complex transmission train of gears, cams and linkage from the plate cylinder which is conventionally driven directly from the prime motor; or by separate independent motors and trans missions. In either case the structures of the transmissions are complex, inaccessible and difiicult to repair and maintain.

Certain of the rolls, namely the distributor rolls, are also axially reciprocated simultaneously with rotation. In the known constructions the axial movement is conventionally obtained by providing a separate and still further independent drive mechanism, transmission levers, etc. just for the axial movement. With such constructions accurate centricity of the rolls is difficult to maintain while simultaneously controlling the reciprocal motion. of course, the problem of access for repair and maintenance is made more difficult.

It is an object of the present invention to provide a roll drive mechanism which is simple and efficient.

It is another object of this invention to provide a roll drive mechanism which simultaneously operates selected groups of rolls.

It is still a further object of this invention to provide a roll drive mechanism which permits easy access to the internal structure of the printing machine for repair and maintenance.

SUMMARY OF THE INVENTION According to the present invention an offset printing machine comprising at least a plate cylinder, a damping roll, an applicator roll and a plurality of distributor rolls is provided. The distributor rolls are conjointly rotated by meshing gears through a central shaft about which they are geometrically arrayed in parallel relationship. Each of the damping rolls, applicator rolls, plate cylinder and shaft is provided with a sprocket wheel. A chain connects each sprocket wheel in a closed loop and drive means are provided whereby each is rotated simultaneously.

In the preferred embodiment the distributor rolls are also freely journaled in a bearing and provided with means for axial reciprocation. As another feature the bearing is dismountable for removal of the rolls.

It is still another object of this invention to provide a structure for group rolls which simultaneously and commonly rotate and axially reciprocates them.

It is an object to provide means for securing rolls within a bearing assembly for simple, easy mounting and dismounting.

The present invention together with the aforementioned objects as well as numerous advantages will be apparent from the following description of the preferred form of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The description makes reference to the accompanying drawings in which:

FIG. I is a side view of the machine showing the axial ends of the roller structure;

FIG. 2 is a section view of the machine shown in FIG. 1 taken along line A-A;

FIG. 3 is a detailed view of the structure shown in FIG. l.

The drawings show as much as an offset printing machine as is necessary for a full understanding of the present invention. The printing machine is otherwise entirely conventional and its nonillustrated features will be readily knowledgable to those skilled in this art.

Referring specifically to the drawings, there will be seen a plurality of rolls supported for operative movement between the upright vertical walls ll of the printing machine frame.

Briefly the apparatus includes a plate cylinder 19, a damping roller 23 for transferring damping liquid from an associated tray to the plate cylinder, an applicator roller 22 for transferring ink from an inking supply, and a cluster of distributor rolls 7 for distributing the ink onto the plate cylinder, as well as associated transfer rollers for the damping fluid and the ink, not numbered.

As will be seen, the distributor rolls 7 are supported in a triangular array, each being provided with extending axles or shafts 7a to which they are conventionally fixed for relative rotation and keyed for conjoint axial movement. The shafts 7a are freely joumaled at each end within a bearing assembly comprising a race 5 and a plurality of balls 6. Each race 5 is located within a circular opening or slot 2 formed in the wall i. The slots 2 are arranged in paired axial position so that the rolls 7 are disposed parallel to each other and to the associated mechanism of the printing machine in a conventional manner. The openings 2 are substantially larger than the outer diameter of the race 5 enabling the distributor roll 7 and the entire bearing assembly to be dismounted with ease from its supported position. The race 5 and consequently the rolls 7, are, however, secured within the opening by insertion of a pillowblock 113 or similar wedge between the outer surface of the race 5 and the inner surface of the opening 2. An adjustable set screw a is threaded within the pillow-block 113 and is adapted to have its head abut, on adjustment, against the inner surface of the opening 2 to fix the assembly in place.

The outer end of each of the distributor roll shafts 7a is provided with a flange in which is fashioned a pair of radial bores 9 and 9a offset approximately with respect to each other. Extending out of the bores 9 and 9a respectively is a guide wheel It) and a cam follower llll. Both the guide wheel 10 and the cam follower llll have stems which are freely located in the corresponding bores 9 and 9a so as to freely rotate therein. The stems are conventionally keyed to the bores 9 and 9a to prevent dislodging of the guide wheel 10 and the cam follower ill while permitting rotation.

Extending axially from the pillow-block 13 are a pair of spaced guide rails 12 which straddle the guide wheel 10 and prevent the distributor roll shaft 70 from rotating although reciprocating movement is permitted.

Because of the keying structure of each distributor roll 7 on its corresponding shaft 70 each roll 7 can be made to rotate about the shaft 7a while simultaneously moving back and forth due to the reciprocation of the shaft 711 in the bearing assemblies.

Located at the center of the triangular array of distributor rolls 7 is a stub shaft 15 journaled in afixed bearing secured in a conventional manner within the outer wall I of the machine frame. The inner end of the stub shaft 115 is provided with a circular gear 27 adapted to mesh with a similar but wider gear 3 secured to each of the distributor rolls 7. Adjacent the outer end of the stub shaft 15 and in proximity with the flanges 8 of the distributor rolls 7 is fixed a drum cam I4 having a grooved cam profile Ma in its face. The drum M is dimensioned to permit the profile of the cam Ma to receive the cam follower roller llll secured to the flange 8. The profile Ma is shaped to induce the distributor roll shaft 7a to axially reciprocate within their bearing assemblies on rotation of the stub shaft 15.

The terminal outer end of the stub shaft is fitted with a fixed sprocket wheel to to which is secured a chain 117. The chain 117 is run over a sprocket wheel lid fixed on the shaft of the plate cylinder 19, the sprocket wheel 2h fixed on the shaft of a damping roll 23 and a sprocket wheel 2i affixed to the shaft of the applicator roll 22 of the inking unit. A spring-loaded idler arm carrying a sprocket wheel 24 is employed to tension the chain l7 and the plate cylinder 19 is conventionally connected by suitable linkage gearing and cam means to the prime motor means of the printing machine whereby all the rolls are moved.

The described mechanism operates as follows:

The rotary motion of the plate cylinder 19 is transferred by the chain 17 to rotate the applicator roll 22, the damping roll 23 and, simultaneously, the stub shaft 15. The stub shaft in turn rotates each of the distributor rolls 7 via the meshing gears 27 and 3 and simultaneously axially reciprocates the roll 7 via the drum cam 14. The guide wheel 10, rolling within the guides 12, prevents the shafts 7a from skewing or turning during movement and assures the mating of the cam follower 11 within the cam profile 14a.

Numerous advantages are obtained by the present construction. For example, all of the damping rolls, applicator rolls and distributor rolls are simultaneously driven by a single drive chain directly from the plate cylinder. Consequently, the complex transmissions, linkages, drive means and cams are eliminated. The need for lubrication is almost entirely eliminated and therefore considerable reduction in downtime for repair and maintenance is effected. The placement of the drive chain and sprocket wheels outside of the frame wall, reduces interference, simplifies construction and makes all of the parts of the printing machine more accessible.

A further advantage is to be found in mounting the shafts of the distributor rolls freely in ball bearing assemblies. The construction permits simultaneous rotation and axial reciprocation without the necessity of providing dual drive means and dual transmissions. Furthermore, with ball bearing assemblies, lubrication needs are reduced. In particular, the construction disclosed permits swift, easy and simple dismantling of the distributor roll for repair and servicing.

Various modifications may be made, particularly to the choice of specific structural elements. Accordingly, the present disclosure is to be taken as illustrative only.

What is claimed is:

l. A drive mechanism for the rolls of an offset printing machine comprising at least a rotating plate cylinder means including a damping roll for transferring damping fluid to said plate cylinder, means including an applicator roll for transferring ink to said plate cylinder, said last-mentioned means including a plurality of distributor rolls positioned between said applicator roll and said plate cylinder for distributing said ink, said distributor rolls being arrayed in a regular triangular pattern parallel to a common central axis, means for mounting each of said distributor rolls on an axle for rotation therewith, means for allowing axial displacement for each of said axles, a shaft joumaled for rotation about said central axis, gear means mounted on said shaft and each of said distributor rolls, said gear means intermeshing to cause conjoint rotation of said distributor rolls, a rotary cam mounted on said shaft, a cam follower mounted on each of said distributor rolls engaging said cam to effect axial reciprocal movement of said distributor rolls, each of said plate cylinder. damping roll, applicator roll and shaft having sprocket means fixed at one end thereof, a closed loop chain operatively connecting each of said sprocket wheels and means for driving at least one of said rolls whereby all are simultaneously driven.

2. The drive mechanism according to claim 1 wherein the rolls are supported within spaced vertical walls of the machine, said sprockets, chain, cam and cam followers being located to the exterior thereof.

3. The apparatus according to claim 2 wherein said shaft is a stub shaft joumaled within one of said walls and wherein said gear means includes a spur gear at one end of said stub shaft and meshing gears at the end of said rolls for producing conjoint rotation.

4. The apparatus according to claim 3 wherein said cam is a drum cam having a shaped profile and each of the said axles of the said distributor rolls is provided with said cam followers extending into said drum cam profile for producing axial reciprocation.

5. The apparatus according to claim 3 including removable bearing means for journaling the ends of said distributor roll axles within the said frame wall whereby the rolls may be quicl cllyl dismantled.

6. e apparatus according to claim 5 wherein said bearings are mounted in oversized openings in the wall and comprise a circular race member having ball bearing means located therein, an insert member surrounding in part said race, and screw means adjustable between said insert and the inner wall of said opening to secure said race therein.

7. The apparatus according to claim 1, wherein the means for driving said chain comprises a motor coupled to said plate cylinder. 

1. A drive mechanism for the rolls of an offset printing machine comprising at least a rotating plate cylinder means including a damping roll for transferring damping fluid to said plate cylinder, means including an applicator roll for transferring ink to said plate cylinder, said last-mentioned means including a plurality of distributor rolls positioned between said applicator roll and said plate cylinder for distributing said ink, said distributor rolls being arrayed in a regular triangular pattern parallel to a common central axis, means for mounting each of said distributor rolls on an axle for rotation therewith, means for allowing axial displacement for each of said axles, a shaft journaled for rotation about said central axis, gear means mounted on said shaft and each of said distributor rolls, said gear means intermeshing to cause conjoint rotation of said distributor rolls, a rotary cam mounted on said shaft, a cam fOllower mounted on each of said distributor rolls engaging said cam to effect axial reciprocal movement of said distributor rolls, each of said plate cylinder, damping roll, applicator roll and shaft having sprocket means fixed at one end thereof, a closed loop chain operatively connecting each of said sprocket wheels and means for driving at least one of said rolls whereby all are simultaneously driven.
 2. The drive mechanism according to claim 1 wherein the rolls are supported within spaced vertical walls of the machine, said sprockets, chain, cam and cam followers being located to the exterior thereof.
 3. The apparatus according to claim 2 wherein said shaft is a stub shaft journaled within one of said walls and wherein said gear means includes a spur gear at one end of said stub shaft and meshing gears at the end of said rolls for producing conjoint rotation.
 4. The apparatus according to claim 3 wherein said cam is a drum cam having a shaped profile and each of the said axles of the said distributor rolls is provided with said cam followers extending into said drum cam profile for producing axial reciprocation.
 5. The apparatus according to claim 3 including removable bearing means for journaling the ends of said distributor roll axles within the said frame wall whereby the rolls may be quickly dismantled.
 6. The apparatus according to claim 5 wherein said bearings are mounted in oversized openings in the wall and comprise a circular race member having ball bearing means located therein, an insert member surrounding in part said race, and screw means adjustable between said insert and the inner wall of said opening to secure said race therein.
 7. The apparatus according to claim 1, wherein the means for driving said chain comprises a motor coupled to said plate cylinder. 